1. Field of the Invention
This invention relates to a filter system such as the type used in removing organic waste from fresh or salt water aquariums or tanks and to facilitate gas exchange between water and atmosphere. It also is applicable to water treatment systems for culturing invertebrates and other forms of sea life. It is a filter system which works on the principle of foam fractionation in which organic or protein waste is separated out of the water of an aquarium or tank rather than breaking it down within the aquarium and to facilitate gas exchange between water and atmosphere. The aquarium or tanks involved are those used for fish, invertebrates, coral, reef animals and the like.
2. Description of the Prior Art
The patent to Gardner, U.S. Pat. No. 3,624,777 discloses one type of fish tank filter generally known as an under-gravel filter.
In Pond, U.S. Pat. No. 3,778,976, contaminated water from the fish tank is fed to a degassing or purifying unit in order to reconstitute the water, after which the reconstituted water is recycled back to the aquarium. The degassing apparatus is provided with a series of baffles which cause the water to flow downwardly in a zig-zag path causing the water to assume a film-like configuration whereby the water surface is maximized, thus resulting in more gaseous interchange when air is blown over the thinned-out water.
Venturi and other type skimmers such as those illustrated at pages 21, 59, 67, 83, 101, 106 and 187 of Volume 18 Number 2, Aquarium Magazine (February 1995) are readily available commercially.